Automatic self-locking differential gearing



MMUHNALD. AU'IUMAHU SEL? wwwa MFFERENHM @Hmm Patented Muy 25, 1920.

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K. P. MMBUNALD.

AUIUMATIC SELF www DWERENHAL GEARING.

AHLICAHUN FILED )UNE 23- |919.

Iltented May 25, 1920.

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4 w if P. MMEUNAU Am'mvmm :Jm- 100mm]INFWRMHALGMRING.

' JILMAHUN HLN) UNL EMU. 1,341,276. muted my 25, 1920.

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uur fnnf'hjmmcboncdcl f I1 uns KENNETH P. MAeIDONALD,

OF LINCOLN, NEBRASKA.

AUTOMATIC SELF-LGCKING DIFFERENTIAL GEARING.

Speclcation of Letters Patent.

Patented May 25, 1920.

Application filed June 23, 1919. Serial No, 306,007.

To all whom it may concern: 1

Be it known that I, Kennern P, MAC- DONALD, a citizen of the UnitedStates, residing at Lincoln, in the county of Lancaster and State ofNebraska, have invented certain new and useful Im rovements in AutomaticSelf-Locking Di erential Gearing; and I do hereby declare the followingto be a full, clear, and exact description oi the invention, such aswill enable others skilled in the art to which. it appertains to makeand use the same,

The present invention relates to ditiemnA tial gearing such as used inautomobiles and other machines for driving two propelling wheels orother driven elements from a common driving shaft or member.

It is the object of the invention to provide a differential gearingwhich will ordi narily distribute the power from the driving member tothe. driven members as needed, rotating one driven member faster orslower than the other, or driving both members at the same speed, andwhich geen ing is provided With improved featuresI of constructionoperable fo automatically locking both of the driven members together soas to rotate as a unit, when there is a tendency for either drivenmember to spin in one direction or the other, due to the freeing of onedriven memliier, such as the disengagement of the propelling wheel fromthe ground, or the like,

A further object is the provision of such a mechanism which will lockthe driven members together when there is an abnormal difference inspeed between the driven menibers. suoli as when one driven member has atendency to spin or rotate at an exceedingly high speed, whereas themechanism loaves the driven members i'ree. to rotate relatively at'normal differences in speed, as when turning corners. In this way` thereis a perfect compensation and equal distribution of the engine power tothe driven members in all conditions, when there is only legitimate ornormal difference in speed for rotation of the driven members or wheels,whereas an abnormal increase of speed in either driven member will looksaid driven members together whereby they will both be rotated as a unitfrom the driving member. thereby preventing the spinning of the drivenmember which may be released or fri-od for any reason whatever, and thusavoiding the waste of power and propulsion oi the remaining drivenmember which is active.

It is also' the object of the invention to embody such improvements indifferential gearing ol prevailing form, and in a simple and inexpensiveyet eflieient and practical manner.

iVith the foregoing and other objects in view, which will be apparent asthe description proreeds, the invention resides in the ronstrurtion and:ii-rangement of parts here inaftei" describe i and Claimed, it beingunderstood that changes fan be made within the scope of what claimedwithout departing from the spirit of the invention.

The invention is illustrated in the accompanying drawing, wherein Figure1 is a diamotrical section of a simple differential 'gearing showing theimprovements embodied therein,

Figj is an elevation of the planetary pinions and clutch members.

Figg 3 is a view similar to Fig. 1 showing the improvements incorporatedin a different forni of gearing,

Fig. 4 is a section on the line 4--4 of Fig. 3, portions being shown inelevation.

In Figs. 1 and :2, a simple form of differentiai gearing is shown, beingof the conventional type, and including the axle see tions or drivenshafts or men'ibers 1 on the adjacent ends of which are keyed the gearwheels 2. A rotatable member 3 inclosing said gear wheels is mounted forrotation on the hubs thereof, and has a gear 4 for connecting thexlifl'erential gearing with a driving shaft, the member 3 constitutingthe driving member of the gearing and carrying a` pair of diametrieallyopposite planetary pinions 5i meshing with the opposite gear wheels :Lthus distributing the power from the driving member to the drivenmembers or shafts 'l with a differential and compensating action, asWell known.

In order to lock the driven members 1 t0 gether when there is a tendencyfor either of them to spin or rotate at a higher speed. than normallyrequired in turning corners or the like, the pinions 5 have inwardlyextending screws or threaded spindles (S projecting toward one anotherand preferably having their adjarent ends irovided ai tb a swivelvonnei'tion as seen in Fig. l. Une of the screws is right handed, andthe other left handed, and on eaeh oll said ,si-rens is threadedlymounted a eluteli member or mit 7 adapted to turn freely on the seri-w,and ol' sufficient weight or bulliY that the momentum will tend toprevent either of' said iiwii'lwi's 7 from turning with theeori'espiindiug Screw should ysaid .si-row spin suddenly. 'lilleadjacent ends` ofl the inen'ibers T are prefer ably provided with elutehteeth to provide a positive grip between said elul'i-h members, and saidmembers are normally separated by a eoiled wire expansion spring 9Surrounding the .arrows (i and inlined be tween said eluteh members, theadjaeent ends of whii-h havereeesses 1l) for reeeiving said spring. Thisspring il is of suilieieut tension to hold said eluti'h members apartduring normal operation. preventing either eluteh member from beingmoved iuwarllv b Y`Serew action due 1o the rolaiioii ol' ilie pinions 5,unless there is asudilen abnormal increase in the speed of said pinions,l

In operation, the gearing will perloini'as usual, the members T rotatingwith the puiions 5 and their screws (i, and the. `spring E) holding saideluteh members apart against any tendentv for them to travel inwardly onthe serews. Should there be an ahnoi mal increase in speed ot eitherdriven inember or shaft 1, this -will increase the lspeed of rotation ofthe pinions 5 about their axes, and the sudden increase in rotationalspeed of the screws 6 will anse one of the eluteh members to moveinwardly into engage ment with the opposite ehiteh member, therebypreventing the further rotation' of the pinions 5 with respert to oneanother` and therefore loueliing the members or shafts 1 together', sothat they will turn as a unit. ln view of the fart that one serew isright handed, and the other lett handed. one of the clutch members willbe t'oreed inwardly should the pinions 5 rotate at an abnormal speed ineither direction, due to the spinning of one member 1 or the other, andsueh action will oeeur during the rotation ot the members 1 in eitherdirection as when mov ing lorwardlv or rearwardly. The reverse serewsprovide for the lor-king' ot the gearing by the rotation of eithermember 1 at a high speed compared with the otherxandl 1n eitherdirei-tion of rotation. Ordinarily, when bolli members l rotate at aboutthe saine speed. the pinions 5 travel around. with. the member 25 andgear wheels 2, but inasmueh as the gear wheels 2 do not have muelirelativelv rotational speed, the pinions 5 have only a slow rotationabout their axes. rl`hus, when turning eoruers, one member 1 will rotatefaster than the other, so that the pinions 5 rotate upon their axes, buttheir speed of rotation is normal or eoinparatively slow, whereas shouldone ot these members be freed or released, said pinions 5 will at oneespin and rotate said member vl at a high or abnormal speed. When thisoeeurs, the A u`dden inert-ase in speed ofthe pinions 5 and their serews(i, will eause the (corresponding rlutrh member T to be foreed in 'ardlyby the artive seri-iv (l, the momentum of such lult-h member preventingit from turning suddenly willi the seri-u', so that the serew turnswithin said rluteh member and fort-es it inwardly into engagement withthe opposite eluteli member against the tension of' the spring i), Theengagement ot the eluteh members locks the pinions 5 together, therebyloelting the gear wheels 2 and members l together as a unit, and notonly preventing the freed member l from spinning, but also applying allthe power to the other memlier l. or to both ot' said members as neededor required. This eondition will be maintained as long as there is atendency for either member l to spin with respect to the other, inasmurhas the tendency for the piiiions :'i to spin will hohl the clutch memhers in engagement, but as soon as the tendenry l'or members l to spinrelatively has passed the spring l) will come into play and separate.the eluteh members thereby releasing the driven members 1 for normaloperation. Centrifugal fori-e will also assist the -spring 9 in movingthe eluteh members outwardly to normal position away from one another,espeeially when the driving member rotates at a high speed, the spring 9being used to assure of suehreturn of the eluteh members under allrenditions. As a, result of using the present construction. the gearingwill operate as usual under normal eonditioiis, and the driven memberswill be locked together whenever and as long as there is a tendenev foreither driven mem bei' to spin or rotati` at an abnormal speed withres-peet to the other, so thatboth driven members will be operated as aunit from the driving n'ieinber, and said driven members will beautomatically unlocked or re' leased from one another when normalconditions are restored. l

In Figs. S and-1, the. improvements are shown in a slightly differentembodiment in another type of di'erential gearing having the drivenmembers or shafts 1l, gear wheels l2 seeured thereon, driving member lilwith its gear 14, and planetary pin'ons 15 carried by said member 13 andmeshing with the gear wheels 12. 1n view of the use of four pinions 15,a simple arrangementshown in Figs. 1 'and 2 cannot be used, unless withonly two of the pinions, and as a means for utilizin all four or morepinions 15, the inner en 'of the s indie or axle 15' of each pinion 15is provi( ed with a reduced inwardly extending screw 16. Th screws ofthe o posits pinions are o'f th same thread, an the screws of one pairar right handed, and of the other pair ar left handed, so that themembers or 'nuts all) il on said Screws operate in pairs at oppositesides oli'tiie axis of the driven members l. Thee members 1T normallycome y,to reet againfit tbe ehoniders at the inner ends ol' thespindles; in.

lilith this modified arrangement, a Short ehatr Ll ie deposed betweenthe members il and han` it;` ende swiveled Within the nir-amers l an at:'32, to Support said shaft or member and elnteh members or sleeves iarealidable on the shaft 2l. and are fea lin-red tbereon so that saidclutch niemianniit rotate relatively, bat can elide ovard and away 'Franone another. The opooaite ende ol raid clutch members and adyarent sidesof the wheels l2 have rlaarh teeth or portions to interengage when saideinteli members are separated, thereby looking both of the gear wheelsl2 to the ehi-itt or member 21, so that Said gear wheels and members 1lwill not rotate relatively. A ring or collar 25 is fitted on the shalt:il between the Clutch members 23, and the erre-ns 1G have stems orlingers QG extending; therefrom and engaging within reifer, in said ringor eollar :25, Coiled Wire expansion springs. li) surround the lingers:2li and are eonlined between the ring 25 and Washers 2*.) slidable onSaid fingers, and the members l? have conical wedges 2S extendingf fromtheir inner sides and bearing against the ivimhers The adjacent Sides ofthe elateb members` 23 are beveled as at E?, for the engagement ol thewedges 2S between the elnt'eli members to separate lbein. The rlntebmembers are normally moved toward one another against the ring A bj;means otl Springs B0 confined between ibe eiateb men'ibers and gearwheels 12, and the sp1-infn lil mamaliy more the members 'i7 oatvvarr ywith the washers 29.

fniler normal conditions. tbe members 1l me rotate at dillerent epeede,and at varyillg,r low :ipeeibs ot the pinions if, the members 17 v ill@imply tarn with the screws l, but @inlaid either shalt or member befreed so as to pim one pair ot members 17 will be nar-,eil inwardlytoward one another by the ,ei-reo aeiion. time forcing,r their wedgesl28 iwi veen the,- vinti-b members 23, and separating' said c-lobhniemllers to move them into engagement with the wheels 12, thus lorliine--aid gear wheels and members il together to rotate im a nnit. ',l`hielooking of the paris will be maintained as lomor as there n a rendi-ivyfor either member l1, to rotate al :l liigli @pei-d relatively to theother, and obra normal renditions are reatored, the paro eill rrlnrn lonormal position. Willen ibo membew` li move inwardly. the waehem frl areHaired lilv'rzviee, thereby eomprefising the prille-a lli. nliirh willreturn members l? barb lo initial position as soon as the il inlener lar:ipinnine' is removed, and the eprinjg ai return the rllitelr members 2Bthereby unlocking the gearing by disconnecting the gear wheels l! fromthe coupling member or :shalt 2l.

Having thas described the invention, what is claimed as new is 'LDili'erential gearing embodying a pair of driven members, planetarypiniona lo- Cated operatively between them, elan-h means for eonnertingTtbe driven members ini-lading members rotatable with Said pinA ions,and. means whereby the excessive epeed of rotation of said pinions willmove one of said members along;r its axis of rotation to bring theelateh into aotion.

2. Diil'erential gearing' embodyiirgr a pair ofrdriven members7planetary pinions lo cated operatively between theme a clutch 'forConnecting the driven members inrludingr rotatable members movable alongtheir axes for bringing the clutch into and out of aetion, and meansoperatively connecting said clutch members'and pinions for rotating'said members with the pinions and upon excessive speed of the pinion tomove one ol said members axially to bring the rlnteh into action.

Differential gearing embodyingr a pair of driven members, planetarypinions if cated operatively between them, a elntrb for connecting thedriven members, and a screw connection between the elnteh and pinionsfor bringing the elnteh into action upon an abnormal relative rotationof said members.

4. Dillerential carineT embodying a pair of driven members, planetarypinions located operatively between said members. a screw movable witheaeh of said pinion and rlnteh means to connect said driven membersincluding' an operativo member threaded on each screw to be moved oponetively by abnormal speed of said pinionn.

Differential gearing' embodying a pair of driven members, planetarypinions lo cated operatively between them, and indev4 pendent meansoperated by :said pinione in the opposite directions of rotation forlimitin;r tbe relative rotational Speed of said driven members in eitherdireetion.

Ga Diil'erential fearingr embodying a pair of driven memlurrs. planetarypiniom` located operatively between :said members, clntrh menne` forlorking tbe driven menibera together to rotaie as a unit. andindependent mean4 operated by said pinions in reverse dirvrtiom4 olrotation lor bringing the rlntrli mean` into :niion in either liYrerlion of rotation.

'7. llill'erential gearing;` embodying a pair of driven members.planetary pinione li rated operativelv between them. reverae Serenararried b 'v said piniona` and rlnlrli meam` for lorliing the drivenmember loretlier ineladinn' member` threaded on ywill .arrows lo bemoved operativi-lv thereby by lll lill] the excessive relativerotational speed of' the driven members in either direction.

8. Differential earing embodying mem,- bers capable of re ativerotation, a, member rotated by the relative rotation of the saidmembers, and havin a srrew, and Ineens for limiting the relatlverotation of the first named members including a `member threzu1- ed onseid screw to be moved operatively thereby by abnormal speed of thescrew.

i). Differential gearing including u pair of members capable of relativerotation, a.

member rotated by such relative rotation of said members and having ascrew, and

clutch means for locking the first named members together to rotate as nunit inelniv ing a member threaded on said screw to normally turntherewith and movable operatively by the screw due to its excessivespeed.

In testimony whereof lV have signed my name to this specification in thepresente of two subscribing Witnesses.

KENNETH P. MACUONL-l).

lVitnesses:

GRACE KILLIP, M. L. EASTERDAY.

